1. Field of the Invention
The present invention relates to a surface-penetration reinforcing agent that is used to effectively repair a damaged reinforced concrete structure and a method for repairing a damaged reinforced concrete structure using the surface-penetration reinforcing agent depending on the aging grade of the reinforced concrete structure. More specifically, the present invention relates to a surface-penetration reinforcing agent including a silicate compound, an acrylate monomer, an amine compound and a silane compound as reactants, and a method for efficiently repairing a damaged reinforced concrete structure using the surface-penetration reinforcing agent depending on the aging grade of the reinforced concrete structure classified by whether or not the reinforcing bars are corroded in damaged portions of the concrete and the degree of carbonation in the concrete.
2. Description of the Related Art
Concrete and steel materials are used in almost every construction industry. Concrete has already proved to have superior formability and workability. Further, concrete has proved to be excellent in terms of quality, such as durability and fire resistance. Based on these advantages, concrete structures have been recognized as being semi-permanent. However, concrete is aged and reinforcing bars are corroded with the passage of time, which make the concrete structures less durable. Such drawbacks of concrete structures are issued as serious social problems. Under theses circumstances, there has been an increasing interest in the maintenance and repair of concrete structures to enhance the usability and stability of the concrete structures.
Many methods have been developed to repair damaged reinforced concrete structures. For example, a damaged reinforced concrete structure is repaired through the following the steps: application of a primer to reinforcing bars, filling of cavities formed in the concrete, and top coating of the surface of the filled cavities. The primer used herein is for the purpose of enhancing the adhesion to a repair mortar for filling the cavities formed in the concrete. As the primer, an epoxy resin, an acrylic resin, a polymer-incorporated cement paste or the like is mainly used. The resinous primer is highly adhesive to concrete at the initial stage of the adhesion. However, since the resinous primer exhibits very different thermal behaviors from the concrete, the adhesion of the primer to the concrete is gradually weakened with the passage of time, resulting in falling of the primer from the concrete. Moreover, the resinous primer leaves a film on the surface of the concrete and has a difficulty in penetrating into the concrete. Accordingly, the primer does not substantially contribute to the reinforcement of the concrete.
Further, a top coating agent is used to prevent occurrence of whitening in the concrete and the repair mortar and to inhibit introduction of water, carbon dioxide and chlorides into the concrete from the outside, thus enhancing the durability of the concrete. Examples of such top coating agents include epoxy and urethane materials. The epoxy and urethane materials serve to prevent elution of water-soluble components together with water to the outside and are effective in inhibiting introduction of the aging factors. In the case where water vapor is generated within the concrete due to the difference in humidity between the inside and the outside of the concrete, the coating formed on the concrete is peeled off by the water vapor escaping to the outside of the concrete and the top coating agent becomes loose or falls off. Furthermore, the use of a solvent in the coating agent causes the generation of a highly toxic smell during coating and even poses a risk of explosion, thus making it impossible to guarantee the safety of workers.
Further, when one method is always employed to repair damaged reinforced concrete structures, unnecessary repair working may be performed regardless of the severity of the damage and the degree of corrosion of reinforcing bars may not be sufficiently reflected.